Question

$Cl—O$ bond order in perchlorate ion is

• A. 1.33
• B. 1.50
• C. 1.75
• D. 1.90

Answer 1

Answer: (C)

Perchlorate ion $(Cl{O}_4^{-})$ exists in fiollowing racemic forms

Thus, $Cl—O$ bond order
$=\frac{\text{Total no. of bonds between two atoms in all resonating forms}}{\text{No. of resonating structures}}$
$=\frac{2\times 3+1}{4}=\frac{7}{4}$
$=1.75$